New LEM current sensor delivers best-in-class charge measurement accuracy for Li-ion EV batteries

One of the biggest issues in the EV sector is the need to develop vehicles that can travel the furthest possible distances between charges and so design engineers are continually searching for sensors that can offer the superior levels of efficiency and accuracy they require. 

The CAB 1500 is the latest member of LEM’s CAB series of automotive grade design sensors that use the properties of fluxgate transducer technology to deliver the high accuracy and low offset required for reliable coulomb counting – measuring the discharging current of Li-ion batteries to estimate their state of charge (SoC). The CAB series is renowned for compliance with the ISO 26262 functional safety standard (to automotive safety integrity level C) as well as easy application through a controller area network (CAN) interface offering 500 kbps. 

Backed by LEM’s 50 years’ experience in developing electrical measurement solutions, the CAB 1500 open loop fluxgate sensor – equipped with electronic mechanisms and software that guarantee the levels of reliability required by BMSs – can be busbar or panel mounted and combines best-in-class resolution up to 0.1% with the lowest offset and highest accuracy.

As well as offering an extended current range up to ±1500A and compatibility with 800V applications to the IEC 60664-1 standard, the new sensor boasts non-intrusive measurement for full galvanic isolation up to 2.5kV. Other features include low power consumption VS shunt technology and 0.5% total error over temperatures from -40°C to +85°C. 

Says Jérémie Piro, Global Product Manager BMS and Battery Storage: “Accurate battery charge level measurement is a crucial factor in being able to maximise the autonomy range of electric vehicles and design engineers will welcome this addition to LEM’s CAB family which offers the kind of performance levels they require. The CAB 1500 uses fluxgate technology to deliver the best SoC estimations on the market for today’s advanced EV battery management systems and will play a key role in enabling electric vehicles to go further than ever.”